Guinness World Records Recognizs NASA X-43A Speed Record

Guinness World Records has recognized the world speed
record set by NASA's hypersonic X-43A aircraft earlier this
year in an experimental flight over the Pacific Ocean. Using
a scramjet engine, the unpiloted, 12 foot-long aircraft
achieved Mach 6.83 -- almost seven times the speed of sound -
- or nearly 5,000 mph, in a March 27 flight.

The accomplishment will be included in the 2006 Guinness
World Records book, set for release this time next year, as
follows:

"On 27 March 2004, NASA's unmanned Hyper-X (X-43A)
airplane reached Mach 6.83, almost seven times the speed
of sound. The X-43A was boosted to an altitude of
29,000 m (95,000 ft) by a Pegasus rocket launched from
beneath a B52-B aircraft. The revolutionary 'scramjet'
aircraft then burned its engine for around 11 seconds
during flight over the Pacific Ocean."

If NASA researchers have their way, the record won't stand
long. The final flight in the Hyper-X program is scheduled to
take place in October, when another X-43A aircraft will
attempt to fly at Mach 10 -- ten times the speed of sound --
or 7,200 mph.

The March 27 flight was part of NASA's Hyper-X program,
designed to demonstrate advanced high-speed propulsion system
concepts to overcome one of the greatest aeronautical
research challenges -- air-breathing hypersonic flight. The
advantage of air-breathing flight is that the vehicle,
whether it is aircraft or spacecraft, scoops the air its
engines need from the atmosphere rather than carrying heavy,
bulky tanks, as rockets do.

The challenge is to introduce fuel, ignite it and produce
positive thrust while highly compressed air rushes through
the engine in mere milliseconds -- roughly analogous to
lighting a match and keeping it burning in a hurricane-force
wind.

Compared to rocket-powered vehicles like the Space Shuttle,
scramjets promise more airplane-like operations for increased
affordability, flexibility and safety in ultra high-speed
flights within the atmosphere and into Earth orbit.

The X-43A flight easily set a world speed record for an air-
breathing engine aircraft. The previous known record was held
by a ramjet-powered missile, which achieved slightly more
than Mach 5. A ramjet operates by subsonic combustion of fuel
in a stream of air compressed by the forward speed of the
aircraft itself, as opposed to a normal jet engine, in which
the compressor section (the fan blades) compresses the air. A
scramjet (supersonic-combustion ramjet) is a ramjet engine in
which the airflow through the whole engine remains
supersonic.

The highest speed attained by a rocket-powered airplane,
NASA's X-15 aircraft, was Mach 6.7. The fastest air-
breathing, manned vehicle, the SR-71, achieved slightly more
than Mach 3. The X-43A more than doubled the top speed of the
jet-powered SR-71.

Guinness World Records' science editor David Hawksett has
already expressed an interest in attending the fall flight.

"Operating an atmospheric vehicle at almost Mach 7 is
impressive enough, but to be able to use oxygen from the air,
instead of a fuel tank, as it screams into the engine intakes
at
5,000 mph is a mind-boggling technical achievement. It's
wonderful to see scramjet technology finally begin to take
off," said Hawksett.

The Hyper-X program is conducted by NASA's Aeronautics
Research Mission Directorate with the NASA Langley Research
Center, Hampton, Va., as lead center with responsibility for
hypersonic technology development and the NASA Dryden Flight
Research Center, Edwards, Calif., responsible for flight
research and testing.

Guinness World Records issued a certificate to NASA
documenting the X-43A accomplishment, and will feature the
story on its web site: